可工作于77 K低温下的CMOS缓冲器

CMOS Buffer Amplifier Working at 77 K

设计了用于制冷型红外读出电路系统的输出缓冲器,该缓冲器能在读出电路5 MHz的读出速度下驱动约20 pF的电容,可以在低温77 K下工作。对运放的增益,频率特性等进行了详细地阐述,并考虑了低温77 K时MOSFET参数的变化带来的影响。最后,给出了修改CMOS常温模型参数后的仿真结果,芯片采用0.35μm,3.3 V CMOS工艺实现,并给出了77 K下的测试结果,满足红外读出电路系统要求。

A kind of output buffer used for cryogenic ROIC was developed, which could drive capacitor of 20 pF at the output rate of 5 MHz and work both at room temperature and 77 K. The gain, frequency and some other parameters of operational amplifier were explicitly interpreted. The effect of MOSFET parameters change was also considered. The simulation results with the modification of CMOS models at room temperature are presented. The design was implemented with 0.35 μm, 3.3 V CMOS technology. The testing results of the buffer at room temperature and 77 K satisfy the demands of ROIC system.